1. Technical Field
The present invention relates generally to the detection of intrusions into security enclosures, and more particularly, to the assembly of a security enclosure capable of detecting intrusions.
2. Related Art
Security enclosures are commonly used in network electronics commerce to transmit encrypted information to authorized persons. FIG. 1 shows a related art security enclosure 8, comprising an electronic assembly 10, which typically comprises a cryptographic processor card within an enclosure, and a tamper respondent wrap or cloth 12. The cloth 12 adheres to the assembly 10 by an adhesive on the inner surface of the cloth 12. The cloth 12 typically consists of several layers of a flexible dielectric having electrical traces or lines (not shown) thereon. Damage to any of the traces within a layer produces a change in resistance which prompts the cryptographic processor card to erase the information stored therein.
As illustrated in FIG. 2, a first side of the cloth 12 is wrapped around the assembly 10. An end 16 of the cloth 12 is inserted within an opening 14 of the assembly 10. The end 16 comprises a plurality of silver filled ink lines formed on the surface of the end 16 to provide an electrical connection between the cloth 12 and the assembly 10. Thereafter, a second end of the cloth 12 is wrapped around the assembly 10, covering the inserted end 16 and over-lapping the first end of the cloth 12 (FIG. 3).
Unfortunately, because the cloth 12 is constructed of multiple layers (not shown) of unreinforced organic dielectric materials which are dimensionally unstable, i.e., susceptible to deformation due to environmental changes, it is difficult to maintain layer-to-layer alignment. As a result, it is difficult to ensure that each layer of the cloth terminates at the end 16, which is necessary in order to make the proper connection with the assembly 10. Likewise, the silver coating at the end 16 is susceptible to electromigration problems, thereby resulting in potential device failure. Furthermore, because the adhesive material on the inner surface of the cloth 10 securely adheres the cloth 12 to the assembly 10 prior to inserting the end 16 into the assembly 10, alignment of the end 16 into the opening 14 of the assembly 10 is often difficult, particularly when the cloth 12 and assembly 10 are slightly misaligned. This may result in device failure due to a poor connection between the end 16 of the cloth 12 and the assembly 10. Likewise, additional forces exerted on the connection over time due to thermal and mechanical stresses, may further weaken the poor connection producing device failure. Moreover, the process of folding the security cloth and inserting the end into the connector is not amenable to automation, thus increasing manufacturing costs. Accordingly, there exists a need in the industry for a security enclosure that solves these and other problems.